eyez, ME1 for the most part (except towards the end) wasn't too bad for intensity of combat in the story.
I could believe Liara joining.
But as a core character, she's not a soldier-type (talking archetypes here now) until, like, nearing the end of ME3, where she and everyone else is forced to fight or die.
Before that, she tried to be more sneaky, more indirect, more spying, more information-gathering. When she joins Shepard, sure, she gets pulled into the fight (she even comments on that), but otherwise she tries to avoid direct conflict.
That's what I mean. If we had an 'adept' themed story, that's probably what we'd be (more) about.
Doesn't mean soldiers can't join us and try to fit our story. That's fine. One can be the most Blue/Paragon/Adept/Indirect/Peaceful Shepard, and friggin Zaeed can still join.
This is the kinda thing I'd imagine, just off the top of my head:
Soldier --> Soldier, duh, overall
Engineer --> Engineer/Architect(of sorts)/Synthetic
Adept --> Scientist/Doctor/Investigator
Infiltrator --> Spy/Investigator/Thief
Vanguard --> Like Soldier but less tied to duty/Free Agent/Leader
Sentinel --> Manipulator/Protector/
Obviously the hybrid classes are harder to pin down, but you get the drift.
But yeah, I think it's still a good model. So we don't get the 'N7 Soldier', oh well, the next game will still likely involve 'N7' (especially given that more recent 'leak' where they asked people what 'N7' meant to them), but I'd consider it to emphasize a more special operations feeling, than the soldier fighting the good fight directly.
More variety, but still not as restrictive as a purely run-and-gun deal, or tied to Shepard's story, is what I've gathered. Could be wrong I suppose.